BOSTON (Reuters) - This city's deepest wound - the 2013 Boston Marathon bombings that killed three and injured hundreds more - will be re-examined Thursday when lawyers for bomber Dzhokhar Tsarnaev seek to have his death sentence lifted because the jury pool was too traumatized to render a fair verdict.

The then-19-year old Tsarnaev and his 26-year-old brother Tamerlan sparked five days of panic in Boston that began April 15, 2013, when they detonated a pair of homemade pressure cooker bombs at the race's packed finish line. The pair eluded capture for days, punctuated by a gunbattle with police in Watertown that killed Tamerlan and led to a daylong lockdown of Boston and most of its suburbs while heavily armed officers and troops conducted a house-to-house search for Dzhokhar.